A magnetic pulse compression power supply is a network including series saturable inductor magnetic switches and a corresponding number of shunt capacitors with each switch and its respective capacitor forming a pulse compression stage. Such power supplies are interconnected between a conventional power source and a load, and function to provide a high current, fast rise time power pulse to the load. The conventional power source is unable to provide such a pulse because of its internal impedance. While it can only provide a relatively slow charge, the conventional power source can be used to energize the capacitors in the magnetic pulse compression power supply, which capacitors can be discharged very quickly.
The saturable inductor magnetic switches used in the pulse compression power supplies typically include a ferromagnetic core having a winding with insulation between the winding and the core to electrically isolate the two. The switches exhibit a relatively high inductance prior to saturation of the core and a relatively low inductance after saturation. While such switches have performed satisfactorily in the past, certain newer types of loads, such as various lasers or gas jet z-pinch devices, demand higher operating voltages and/or repetitively pulsed operation. The prior art switches are unable to meet these requirements and still exhibit long service life.
A figure of merit for a saturable inductor magnetic switch is the ratio of inductances before and after saturation of the core; the higher the ratio, the better the switch. The ratio can be maximized by minimizing the amount of insulation between the winding and the core, because less insulation results in better coupling of the magnetic flux to the core material. However, at higher voltages, more insulation is required to prevent voltage breakdown. Another way to improve the ratio is to increase the cross-sectional area of the core which reduces its magnetic path length relative to its volume. However, an increase in cross-sectional area while maintaining the total volume of the core results in a reduction of the core surface area for radiating heat. Thus high voltage magnetic switches often have cooling problems when operated at high repetition rates. Of course, the core must be maintained below its Curie temperature (which could be 200.degree. C. or less) if it is to retain its ferromagnetic properties.
A recently proposed switch, for use in a pulse-forming network for supplying power pulses to an electric discharge gas laser, is integrated with lengths of coaxial cable which provide distributed capacitance. The magnetic core for this saturable inductor switch is wound of a laminate including a layer of high permeability material required to have a skin depth in the order of one to two microns. For further information regarding the structure and operation of this saturable inductor switch, reference may be made to U.S. Pat. No. 4,275,317.